clark



RRRRRRRRR APPLICATION FILED DEC.4, 19M. Patented Aug 4 SHE; TTTTTTTT I.

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ROCK DRILL.

APPLICATION FILED BECA. 1314. 1,314,246. Patented Aug. 26,1919.

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RocK DRILL.

APPLICATION rlLzuvnEc. 4, 1914. Patented Aug. 26,1919" 4 SHEETS-SHEET 3.l

O. E. CLARK. RoK DRILL.

Patented Aug. 26,1919.

4 SHEETS-SHEET 4.

ILlIl.

H n l@ UNITED STATES PATENT OFFIOE.

OMAR E. CLARK, OF DENVER, COLORADO, ASSKIGNOR TO THE DENVER ROCK DRILLMANUFACTURING COMPANY, 0F DENVER, COLORADO, A CORPORATION OF DELA- WARE.

ROCK-DRILL.

Specification of Letters Patent.

Patented Aug'. 26, 1919.

Application led December 4, 1914. Serial N o. 875,465.

To all 'Lv/tom t may concern.'

Be it known that I, OMAR E. CLARK, ar

citizen of the United States, residinfr at Denver, in the county ofDenver and State of Colorado, have invented new and useful Improvementsin Rock-Drills, .ofwhich the following is a specification.

The present invention relates to drilling4 apparatus of the hammer type,and in a specific sense, to that in which a valveless motor is employed,together with means forautomatically rotating the tool-holding chuckfrom the piston.

Considerable diiiculty has developed in producing a valveless machinethat will effect the automatic rotation. This is primarily forv thereason that rwith a valve-v n piston, with the result that there is agradual reduction of the amount of movement of the piston until a pointis reached when an' elfective blow is not struck, and the tool isv notrotated. y

One of the primary objects of the invention is to provide an effectivemechanism that is not open to these objections, 4will strike a powerfulblow, and is economical in the consumption of motive-Huid.

An embodiment of the invention is illustrated in the accompanyingdrawings, wherein Figure 1 is a plan view of the tool.A

Fig. 2 is a longitudinal sectional view therethrough, .with the pistonat the end of its forward or working stroke. A A

Fig. 3 is a similar view, with the piston in its rear position.

Fig. L is a cross sectional view on the line 1 4 of Fig. 3.

Fig. 5 is a rear elevation of the machine.

Fig. 6 is a cross sectional view on the line v 6 6 of Fig. 3.

Fig. 7 is a detail sectional view on the line 7-7 of Fig. 4.

Fig. Sis a perspective view of one of the feathers for holding thepiston against rotation.

Figs. 9 and 10 are longitudinal sectional views, illustrating therelation of the ports when the piston is in different positions.

Figs. 11 and l2 are, respectively, cross sectional views on the lines11-11 and 12`12 of Fig. 2.

Fig. 13 is a perspective view of the piston.

Figs 14, 15 and 16 are detail perspective views of the ratchet mechanismand the chuck, with portions broken away, to illustrate the internalconstruction thereof.

Fig. 17 is an end elevation of the pawlcarrying ring.

Fig. 18 is a sectional view therethrough on the line 18-18 of Fig. 17.

Similar reference numerals designate corresponding parts in all thefigures of the drawings.

In the embodiment disclosed, a cylinder member is employed, comprising abarrel or body A19 having a .bore 20, in which is slidably mounted areciprocatory piston 21. The said cylinder barrel also has an enlargedbore 22 in rear of the bore 20 and in direct communication therewith. Aspacing block 23 is located upon the front end of the barrel 19, andconstitutes in effect a head for the same, this block having a reducedbore 24 therethrough, and having mounted on its front end a chuck casing25. Located upon the rear end of the barrel 19 is a lubricant reservoir26, and abutted against the sameV is the integral flange 27 of a supplytube 28, hereinafter described. This flange 27 is clamped against thereservoir 26 by a rear head plate 29, and all the above parts aresecured in position by side bolts 30, which pass through the head plate29 and through ears 31 formed upon the rear portion of the chuck casing25.

The piston 21 is provided with a forwardly extending projection 32 ofless diameter than said piston, said piston is furthermore provided withan internal constant pressure chamber 33 having a reduced rear bore 34;that opens through its rear end. The tube 28 is slidably engaged in saidbore 34, and its front end opens into the chamber 33, said tubeconstituting means for conveying fluid under pressure to the constantpressure chamber 33 and maintaining it therein. The tube 28 is suppliedfrom any suitable source. In the embodiment disclosed, a nipple 35 isshown connected to the head plate 29, havinv a bore 36 communicatingwith a chamber 37 formed in said plate 29, which chamber is incommunica-tion with the tube 2S. A hose may be connected to the nipple35 in the usual manner, and a throttle valve 38 for controlling thesupply is located in said nipple.

For the purpose of distributing the fluid under pressure from thechamber 33 to opposite faces of the piston, forwardly inclined ports 39open from the front portion of the chamber 33, through the walls of thepiston, and the outer ends of these ports are movable into and out .ofcommunication with enlargements 40 formed in the front portions of thecylinder walls. Rear-wardly extending ports 41 also open from the rearportion of the constant pressure chamber 33, through the walls of thepiston, and these ports are movable into and out of communication withthe enlarged chamber or bore 22. The exhaust takes place throughlongitudinal passageways 42 formed in the cylinder walls, saidpassageways having spaced ports 43 and 44 opening into the pistonchamber. The rear ports 43 are arranged to have communication with thechamber 22, through grooves 45 cut longitudinally in the rear portion ofthe piston, and the ports 44 are uncovered and covered by the front endof the piston during its reciprocation.

Brie-fly described, the operation of the machine as thus far set forthis as follows. If fluid under pressure is supplied to the internalpressure chamber 33, and assuming the parts are in the position sho-wnin Figs. 3 and 9, it will be evident that the fluid will escape from thechamber 33, through the ports 41 into the Chamber 22, and thus operateaga-inst the rear face of the piston. In addition there will, of course,be pressure against the front wall of the internal chamber 33, and thepiston will be driven forwardly. During this forward movement theexhaust in advance of the piston can take place through the ports 44 andpassageways 42. As the piston advances, the ports 44 will be covered,and the exhaust thus cut off, as shown in Fig. 10. At the same time, thegrooves 45 will open communication between the chamber 22 and the ports43, so that an exhaust can take place therein in rear of the pistonchamber. Vhen the parts are in this position, the ports 39 will be incommunication with the enlargements 40, and consequently fluid underpressure will enter the front end of the piston chamber in advance ofthe piston. The piston will now be driven rearwardly, and as thisoperation is repeated, the piston will, of.

course, reciprocate with rapidity.

The following mechanism is employed for securing the rotation of thetool. Said tool, a portion of which is shown at 46, may be of any wellknown character, and is detaehably'mounted in a rotatable chuck sleeve47. This chuck sleeve has a rear outstanding flange 48, which operatesagainst an in` ternal shoulder 49 in the chuck casing 25, said shoulderthus preventing longitudinal forward displacement of the sleeve. Thesaid flange has on its rear face a plurality of teeth 50, shown moreparticularly in Fig. 16, and an extension ring 51, located in rear ofthe chuck sleeve and interposed between the same and the spacing block23, is provided with forwardly projecting teeth 52 that are interlockedwith the teeth 50. The extension, therefore, while readily detachable,is held against relative rotation with respect to said sleeve, as willbe obvious. This ring 51 is provided with an internal series of ratchetteeth 53. Rotatably mounted within the ring 51 is a pawl-carrying ring54 having hub portions 55, one of which is jo-urnaled in an inturnedflange 56 formed in the front end of the ring 51, the other beingrotatably mounted in the front end of the spacing block 23. The ring 54is provided with a plurality of tangential slots 57, in which areslidably mounted pawls 58 that are urged outwardly by suitable springs59 located behind them. The outer ends of these pawls 58 cooperate withthe ratchet teeth 53. The bore of the ring 54 is provided with aplurality of spiral feathers 60 that are slidably engaged with spiralgrooves 61 formed longitudinally in the face of thev reduced extension32 of the piston.

The body of the piston is also provided with longitudinal straightgrooves 62, in which are engaged feathers 63 detachably secured to theinner face of the cylinder barrel 19. To this end, said feathers areprovided with outstanding portions 64 lthat project through openingsformed in the barrel 19 and have holding nuts 65 threaded on theirprojecting ends. The feathers 63 are furthermore held against lateraloscillation or displacement by dowel pins 66 carried thereby and engagedin sockets 67 formed in the walls of the cylinder barrel 19.

By referring to Fig. 4, it will be noted that the feathers 63 with theirygrooves 62, the grooves 45 and the ports 39 and 41 are spacedequidistant aro-und the piston, so that they do not interfere with oneanother, andthe danger of leakage is reduced to a minimum.

It is thought that the operation of the above described portion of themechanism can now be made clear. Assuming the piston in operation, asabove described, it will also be noted that said piston is positivelyheld against rotation, or in other words, has a rectilinear movement. Asthe extension moves forward, it will strike a blow against the tool 46.During the forward movement, the feathers 60 engaged in the spiralgrooves 61 in the piston extension will cause the pawl-carrying ring 54to partially rotate, and the pawls 58 engaging with the ratchet teeth 53will effect a corresponding movement of the extension ring 51, andconsequently of the chuck sleeve 47. This movement will furthermore betransmitted to the tool. On the return movement, the pawl-carrying ring54 will be turned in the opposite direction, and the pawls willvrideover the teeth 53. The piston thus will, through the medium of theratchet mechanism, effect a step-by-step rotation of the chuck and thetool located therein.

As heretofore pointed out, one of the serious difficulties in eecting anautomatic rotation from the iston of a valveless hammer has been the diculty of securing sufficient power to carry the piston across its deadcenter when the frictional resistance of the rotating mechanism is addedto that -of the other parts. One of the important features of thepresent case is the provision of means which aids materially inovercoming this difficulty. This means is preferably constructed asfollows: The rear end of the piston 21 is provided with a reducedextension 68 that passes across the enlarged bore or chamber 22 and isarranged to enter a pocket 69 formed in the rear head member 26, therear wall of said pocket being formed by an enlargement 7 0 of the tube28, which enlargement terminates short of the inner end of the head 26.By reference to Fig. 9, it will be noted that the distributing ports 41are solocated at a distance from the rear end of the extension 68 thatthey will be uncovered during the rear stroke of the piston before theextension 468 enters the pocket 69.

It will also be clear, particularly by reference to Fig. 10, that thedistributing ports 41 will be closed on the forward stroke of the motorbefore the exhaust ports 43 are opened by the grooves 45.

It will thus be seen that on the rearward stroke of the piston, theports 41 .are opened early enough to allow the reservoir chamber 22 andthe pocket 69 to fill with fluid under initial pressure before theextension 68 enters the said pocket 69. Consequently when it does entersaid pocket, it operates against Huid under initial or nearly initialpressure to start with, and it will be obvious that this pressure willrun up very high by the time the piston comes to a stop. It is thereforeimmediately given an impulse in the forward direction, and at the pointwhere the extension 68 leaves the pocket 69, the speed is much greaterthan it was at the time it entered. This is for the reason that inaddition to this extremely high pressure acting on the extension whichhas entered the cushion pocket there 1s also initial pressure act- Aingon the remainder of the rear face of the mer at the beginning of itsstroke, and the piston speed is increased at every point in the forwardstroke by the expansion of the motive Huid in the reservoir 22, so thatit not only has inertia sufficient to carry it over the dead center, butalso to deliver a proper blow and effect the rotation of the chuck anddrill bit. The parts 68 and 69 therefore perform two functions, namely,a cushioned stop to the hammer with minimum jar and vibration andgreatly adds speed and power to the piston. l

From t-he foregoing, it is thought that the construction, operation andmany advantages of the herein described invention will be apparent tothose skilled in the art, without further description, and it will beunderstood that various changes in the size, shape, proportion and minordetails of construction maybe resorted to withoutdeparting from thespirit or sacrificing any of the advantages of the invention. f

Having thus fully described my invention, what I claim as new and desireto secure by Letters Patent, is

1. In apparatus of the character set forth, the combination with acylinder member and a piston having a back and forth movement therein,of means for permitting the exhaust from the cylinder member alternatelyon opposite sides of the piston, means independent of the exhaustpermitting means for supplying motive fluid to the cylinder memberalternately on opposite sides of the piston and including motive fluidconducting means carried by the piston and moving wtherewith beyond theexhaust .permitting vmeans but out of line with the same, and

means for holding the piston against turning in the cylinder member toprevent said piston carried conducting means from communicating with theexhaust permitting means.

2. In apparatus of the character set forth, the combination with acylinder member and a piston having a back and forth movement therein,of means for permitting the exhaust from the cylinder member alternatelyon opposite sides of the piston, means independent of the exhaustpermitting ine-ans for supplying motive fluid to the cylinder memberalternatively on opposite sides of the vpiston and including motivefluid conducting means-carried by the piston and moving therewith beyondthe exhaust permitting means but out of line with the same, drill bitrotating means engaged with and operated by the piston on its back andforth movement, and means for holding the piston against turning in thecylinder member, to prevent said piston carried conducting means fromcommunicating with the exhaust permitting means and securing therotation of the drill operating means by said piston.

3. In apparatus of the character set forth, the combination with acylinder member having a 1piston chamber, of a reciprocatory hammerpiston operating therein and comprising a head operating in the pistonchamber, said head having a reduced exten sion, a rotary tool holdingchuck, means between the extension and chuck and slidably engaged by theformer for effecting the rotation of the latter, means for holding thepiston to a fixed path comprising a groove in the peripheral portion ofthe piston head that terminates short of one end of the same, leaving asmooth peripheral end portion to said head that has a sliding lit in thepiston chamber, and an inwardly extending feather carried by thecylinder member and engaging in said groove.

l. In apparatus of the character set forth, the .combination With acylinder member and a reciprocatory hammer piston operating therein andcomprising a head having areduced extension, said extension having acontinuous set of, spiral grooves and ribs around its periphery, theribs being generally of the cross sectional shape and size of thegrooves of a chuck, chuck rotating means including a ring surroundingthe extension and having a continuous internal set of correspondinggrooves and ribs coacting with the grooves and ribs of the extension,and a feather carried by the cylinder member, said piston h( ving agroove that receives the feather to hold said piston to a fixed path,the said piston groove terminating short of one end of the piston andsaid end having a smooth unobstructed lit in the cylinder.

In apparatus of the character set forth, the combination With a cylindermember, of a reciprocatory piston operating therein and having aninternal constant pressure chamber provided With a front constantpressure face formed upon the piston, means for constantly supplyingliuid under pressure to the chamber, sets of ports for respectivelysupplying fluid from the constant pressure chamber to opposite ends ofthe piston and for exhausting the same from said ends, said sets beinglocated in diierent longitudinally and axially disposed planes, andmeans for holding the piston to a predetermined path of movement andthereby preventing the supply and exhaust ports from being broughtintothe same relative planes.

6. In apparatus of the character set forth, the combination with acylinder member, of a reciprocatory ypiston Operating therein and havingan internal constant pressure chamber provided with a front constantpressure face formed upon the piston, means for constantly supplyingliuid under pressure to the chamber, ports in the piston Walls forrespectively supplying fluid from the constant pressure chamber toopposite ends of the piston, ports in the cylinder Walls and out 0f linewith the piston ports for exhausting the fluid from the ends of thepiston, and means for holding the piston to a predetermined path ofmovement and preventing the supply and exhaust ports from being broughtinto the same relative planes.

7. In apparatus of the character set forth, the combination with acylinder member, of a reciprocatory piston operating therein and havingan internal constant pressure chamber `provided with a front constantpressure face formed upon the piston, means for supn plying fluid underpressure to the constant pressure chamber, a chuck, means for effectingthe automatic rotation of the chuck from the piston, means fordistributing the fluid from the constant pressure chamber to reciprocatethe piston, and means for insuring the continuously repeated fulloperative strokes of the piston by the fluid so distributed to deliverhammer1 blows to a bit placed in the chuck While effecting rotation ofthe chuck.

8. In apparatus of the character set forth, the combination With acylinder member, of a reciprocatory piston operating therein and havingan internal constant pressure chamber provided with a frontoonstant'pressure face formed upon the piston, and means for supplyingfluid under pressure to the constant pressure chamber, a chuck, afeather engagement between the cylinder member and piston, passagewayscommunicating With the constant pressure chamber and controlled by themovement of the piston when guided by the feather engagement forsupplying fluid from the chamber to opposite faces of the piston toreciprocate the same, and means having a feather engagement With thepiston to effect the rotation of the chuck.

9. In apparatus of the character set forth, the combination with acylinder member, of a reciprocatory piston operating therein and havingan internal constant pressure cham ber, means for supplying fluid underpressure to the constant pressure chamber, said piston having aprojection of reduced diameter on its front end, means engaged with thebody 0f the lpiston for holding it against rotation, means cooperatingWhen the piston is held against rotation, for distributing the iuidunder pressure in the constant pressure chamber to reciprocate thepiston, a ratchet chuck, and ratchet mechanism engaged With the reducedportion of the piston for effecting a stepby-step rotation of the chuck.

10. In apparatus of the character set forth, the combination with acylinder member having a piston chamber, of a reciprocatory pistonmember therein, one of said members having a cushion pocket incommunication with the piston chamber, the other having a Iportion thatenters the pocket, means for introducing fluid under pressure into thepiston chamber and pocket prior tothe entrance of the said portionthereinto, and drill bit rotating mechanism driven by the piston.

11. In apparatus of the character set forth, the combination with acylinder member having a piston chamber and a reduced rear pocketopening into the same, of a reciprocatory piston operating in the pistonchamber and having a reduced rear extension movable into and out of thepocket, means for exhausting the motive uid from the piston chamber inrear of the piston during the latters rearward stroke, means forintroducing iuid into the chamber in rear of the piston prior to theentrance of the extension into the pocket, whereby said extension trapsfluid under substantially initial pressure when it enters the pocket,and drill bit rotating` mechanism driven by the piston.

12. In apparatus y0f the character set forth, the combination with acylinder member having a piston chamber, of a reciprocatory pistonmember therein, one of said members having a cushion pocket incommunication with the piston chamber, the other having a portion thatenters the pocket, means for introducing Huid under pressure into thepiston chamber and pocket prior to the entrance of the said portionthereinto, a rotatable tool holding chuck, and means for rotating saidchuck from the piston.

13. In apparatus of the character set forth, the combination with acylinder member having a piston chamber and a reduced rear pocketopening into the same, of a reciprocatory piston operating in the pistonchamber and having a reduced rear extension movable into and out of thepocket, means for exhausting the motive fluid from the' piston chamberin rear of the piston during the latters rearward stroke, means 'forintroducing fluid into the chamber in rear of the piston prior to theentrance of the extension into the pocket, whereby said extension trapsfluid under substantially initial pressure when it enters the pocket, arotatable tool holding chuck, and means for effecting an automaticstep-by-step lrotation of the same from the piston on the forward strokeof said piston.

14. In apparatus of the character set forth, the combination with acylinder member having a piston chamber and a reduced rear pocketopening into the same, of a reciprocatory piston operating in the pistonchamber and having a reduced rear extension movable into and out of thepocket, and an enlargement or reservoir pocket for the storage ofexpansive motive Huid, means for exhausting the motive fiuid from thepiston chamber in rear of the piston at the end of the latters forwardstroke, means for introducing fluid into the chamber in rear of thepiston prior to the entrance of the extension into the pocket, wherebylsaid extension traps fluid under substantial initial pressure whenitenters the pocket, a rotatable tool holding chuck, and means foreffecting an automatic step-by-step rotation of the same from the pistonon the forward stroke of said piston.

15. In apparatus of the character set forth, the combination with acylinder member and a piston operating therein and having a grooveterminating short of one end thereof, said piston comprising a head anda reduced portion projecting therefrom, of means carried by the cylindermember and engaged in the groove of the head for holding the pistonagainst oscillatory and rotary motion while permitting itsreciprocation, the grooveless end portion of the head having a smoothsliding fit in the cylinder mem- S5 ber, means carried by the piston andcylinder member and maintained in coacting relation by the pistonholding means for alternately delivering motive Huid to and exhaustingit from opposite surfaces of the head, a rotary chuck for holding thetool, said reduced portion operating in the tool, and means engaged withthe reduced porktion for rotating the chuck.

16. In apparatus of the character set forth, the combination with acylinder meinber having a piston chamber provided with. front and rearinternal recesses, of a reciprocatory piston operating in the chamberbetween the recesses, means in the piston alternately communicating withthe recesses for distributing motive fluid therethrough to opposingfaces on the piston, an exhaust port opening into the chamber ,betweenthe recesses and out of line therewith. and means for holding the pistonagainst turning to prevent the distributing means in the pistoncommunicating with the exhaust port.

17. In apparatus of the character set forth, the combination with acylinder member having a piston chamber provided with front and rearinternal recesses, of a reciprocatory hammer piston operating in thechamber between the recesses and including a head having a reducedextension, means in the piston head alternately communicating with therecesses for distributing motive fluid therethrough to opposing faces onthe head, an exhaust port opening into the piston chamber between therecesses and out of line therewith, and a feather engagement between thecylinder member and head to hold the latter from turning and therebypreventing the distributing means in the piston communicating with theexhaust port.

18. In apparatus of the character set forth, the combination with acylinder member having a piston chamber provided with front and rearinternal recesses, of a reciprocatory piston operating in the chamberbetween the recesses, said piston comprising a head and a reducedextension, means in the piston alternately communicating with therecesses for distributing motive fluid therethrough to opposing faces onthe piston, an exhaust port opening into the chamber between therecesses and out of line there- 'with, a drill bit chuck, means operatedby the extension for rotating the chuck, and a feather engagementbetween the cylinder member and piston head to hold the latter againstturning and preventing the distributing means in the piston fromcommunicating with the exhaust port.

19. l'n apparatus of the character set forth, the combination with acylinder member, of a piston operating therein and comprising a headhaving a. reduced extension provided with grooves, ports and passagesfor delivering motive fluid to and permitting its exhaust from oppositefaces of the piston, said ports and passages being controlled directlyby the piston on its movement, a ring engaged with the grooves, meansfor holding the piston to a fixed path of movement, said piston on eachreciprocation effecting a relatively slight oscillation of the ring, arotatable chuck, means for effecting the rotation of the chuck from theoscillation of the ring, and means for insuring the repeated continuousfull working strokes of the piston under the action of the motive fiuidand notwithstanding the drag of the rotating means.

20. In apparatus. of the character set forth, the combination with acylinder member, of a piston operating therein and comprising a headhaving a reduced extension, said extension having longitudinal groovesand ribs, disposed on a slight spiral, a member on said extensionengaged with the ribs and grooves and given a slight oscillatorymovement upon each reciprocation of the piston, means engaged with thepiston head for holding it to a fixed path of movement, a chuck, meansfor imparting rotary movement to the chuck from the oscillating member,ports and passages for delivering motive fluid to and permitting itsexhaust from opposite faces of the piston, said ports and passages beingcontrolled directly by the piston on its movement, and means forinsuring the repeated continuous full working strokes of the pistonunder the action of the motive fluid and notwithstanding the drag of therotating means.

In testimony whereof I have hereunto set my hand in presence of twosubscribing witnesses.

OMAR E. CLARK. Witnesses: Y

WILLIAM A. LEONARD, JAMES B. ELMENDORF.

Copies of this patent may be obtained for five cents each, by addressingthe Commissioner of Iatents,

Washington, D. C.

